Grinder for hard cellular plastic or the like



8" 22, 1967 A. F. KEYS ETAL 3,337,141

GRINDER FOR HARD CELLULAR PLASTIC OR THE LIKE Filed Aug. 4, 1964 2Sheets-Sheet 1 IHWHWIIWIIWWH 4 THOMAS E ORMSBY ARCHIE F. KEYS IINVENTORS THEIR AGENT Aug. 22, 1967 A. F. KEYS ETAL 3,337,141

GRINDER FOR HARD CELLULAR PLASTIC OR THE LIKE 2 Sheets-Sheet 2 FiledAug. 4,, 1964 N .i i wm mm MIT? m S K m3 m T m on 3 WWW in N A om M m vAE mm m 7 mm 2 I 9 Y L B w. N\ mm vm mm j 1! I m v m M t o. I r mm w mm7 m 2 m {mm v m M v 3 -m .TN .IJIH. M N .M

United States Patent 3,337,141 GRINDER FOR HARD CELLULAR PLASTIC OR THELIKE Archie F. Keys, 300 W. 7th St., and Thomas F. Ormsby, 2908 W. 11thSt., both of Plainview, Tex. 79072 Filed Aug. 4, 1964, Ser. No. 387,4242 Claims. (Cl. 241-88) This invention relates to an apparatus forgrinding pieces of hard cellular plastics, which is usually known in thetrade as styrofoam or the like, so as to disintegrate this into amaterial which is slightly coarser than normal sawdust, so thedisintegrated material may be used in flower pots, for packing, and thelike.

This invention is particularly adaptable for use in shops which utilizestyrofoam and where scraps are left which are not sufficiently large forthe original use. The present apparatus is especially adaptable for usein flower shops, which use styrofoam on which to create floral designs,as such shops usually have a considerable quantity of styrofoam whichmay be readily disintegrated into usable material, as set out above.

The present invention is so constructed that it may be readily clampedto a bench, table, shelf, or the like, to perform a grinding action onsuch material as needed and then the device can be removed and stored soas to be out of the way.

The present device may be powered by a small gear re duction motor, suchas a hand drill or the like. Powering the present device with a handdrill makes it possible to hold the cost to a minimum, as the hand drillcan double for the drive motor on the present device and for normaldaily use as a hand drill.

The device isso constructed that it may be readily dismantled for repairand replacement of parts, or for the sharpening of the saw or graterblade, should such sharpening become necessary.

Furthermore, the device is constructed with a relatively small intakeopening, and with a relatively deep throat, so as to preclude thepossibility of getting a hand into the hopper of the device, therebypractically eliminating a portion of the hand becoming mangled by thesaw teeth. Furthermore, a protective elastomer door is secured on thedevice which will permit the entrance of styrofoam blocks or the likeinto the hopper of the device. However, upon trying to insert the handthrough such opening, the cover gives. ample warning of the existence ofthe opening.

An object of this invention is to provide a disintegrating machine whichmay be readily set up in a small space and which may be operated withoutthe necessity of having a large mill to grind the styrofoam intosawdust-like material. 7

Another object of the invention is to provide a grinding mill which willreadily grind up scrap blocks of styrofoam into sawdust-like materialfor use in flower pots, for packing and the like.

Still another object of the invention is to provide a mill for grindingstyrofoam into sawdust-like material, which mill is small, compact andwhich may be readily driven by a small drill motor.

Still another object of the invention is to provide a styrofoam grinderor grater which utilizes a cylindrical drum, having spirally arrangedsaw teeth thereon to disintegrate styrofoam into relatively small bits,similar to sawdust, or the like.

Another object of the invention is to provide a styrofoam grinder or thelike which has a cushioned lining therein to minimize chattering noiseduring the grinding operation.

Another object of the invention is to provide a styro- 3,337,141Patented Aug. 22, 1967 2 foam grinding mill that is simple inconstruction, low in the cost of manufacture, easy to assemble anddisassemble, and relatively trouble free in operation.

With these objects in mind and others which will become manifest as thedescription proceeds, reference is to be had to the accompanyingdrawings in which like reference characteristics designate like parts inthe several views thereof, in which:

FIG. 1 is a perspective view of the device, showing a sack or othercontainer therebelow, in dashed outline;

FIG. 2 is a sectional view taken on line 22 of FIG. 3, with parts brokenaway and with parts shown in e1evation to bring out the details ofconstruction;

FIG. 3 is a sectional view taken on line 33 of FIG. 2, looking in thedirection indicated by the arrows, portions thereof being shown indashed outline, to indicate the feeding of scrap styrofoam blocksthereinto, the elastomer safety door being shown in depressed conditionin dashed outline, and also showing a receptacle, such as a sack,attached to the lower end of the styrofoam mill by a rubber band or thelike; and FIG. 4 is a fragmentary view of the open, grater-like materialof expanded metal for use in the bottom of the device. I

With more specific reference to the drawings, the numeral 1 designatesgenerally a styrofoam grinding mill showing a gear reduction motor 2attached thereto for operation thereof, which, in the present instance,is shown to be a hand drill. The numeral 4 designates the side plates onwhich is secured C-clamp members 6 which are secured to a side thereof,as by welding, to enable the grinding mill 1 to be attached to a shelf,table, bench or the like, as indicated at 8.

A front portion 10 is formed, as will best be evident in FIGS. 1 and 3,to be positioned between the forward portion of the side plates 4 and aback portion, as indicated at 12, is positioned intermediate the sideplates 4 on the rear side thereof.

Each side plate 4 is apertured at the top, on each side thereof, and atthe bottom, which aperatures receive bolts or studs 13 therethrough tobindingly engage the side plates 4 in secure relation to the frontportion and to the back portion 12. The front portion 10 has a mentrantportion 9, which forms a guideway for styrofoam blocks 26. The lower endof the front portion 10 has an upwardly curved portion 11, which isadapted to surround front boss 11a which is impressed into each side ofeach side plate near the lower end thereof. The back portion 12 has adownwardly and inwardly re-entrant portion 12a so as to form a backingfor elastomer liner portion 32. The back portion 12 extends downwardinto close proximity to the points of teeth 24, with an offset portionto allow an end of the semi-cylindrical, expanded metal bottom to extendupward between the back portion 12 and the rubber liner portion 32, sothat teeth 33 of the liner portion will come into very close proximitywith teeth 24, when the cylinder 18 is rotated. The liner portion 32extends upward over the uppermost bolt 13 with a portion 35 extendingdownward to at least partially close the upper throat 25. The backportion 12 has an upwardly curved re-entrant portion 12b on the lowerend thereof to surround opposed bosses 11a on the rear of side plates 4.

Each side plate 4 has a bearing sleeve 14 therein, near the lower endthereof, to receive a shaft 16 to which drum 18 is secured for rotationtherewith. A saw or. grater blade 20 has a flat portion turned outwardat a substantially right angle to the teeth 24 thereof, which fiatportion is perforate near each end to receive screws 22 therethrough toattach the saw or grater blade 20 to the cylinder 18 in a spirallyarranged position, so that the teeth 24 will be upstanding therefrom toengage the sty-rofoam blocks 26, so upon rotation of cylinder 18 thestyrofoam blocks will be disintegrated into sawdust-like material, uponrotation of the cylinder 18 by the motor 2. Each side plate 4 has aconcave, annular ring 28 surrounding bearings 14 and spaced therefrom soas to be co-axial with the bearings 14. This annular, concave ring 2 8is adapted to receive an arcuate, perforate, semi-cylindrical member 30,which is preferably made of nonflattened, expanded metal, with a portionof the metal having slots formed therein, which are arranged with thelength of the slots in parallel, aligned relation with the axis of shaft16, with the inner arcuate surface of the semi-cylindrical member 30being spaced in close proximity to the points of teeth 24 so that anypieces of styrofoam which finds its way downward between the elastomerback 32 and the cylinder 18 will be sawed or grated by saw teeth 24until the disintegrated material will fall through the openings 34 insemi-cylindrical, expanded metal member 30, thence downward through anopen end 36 into a sack or container 38 which is secured to the lowerend of side plates 4 by a rubber band 40, or the like, Each side plate 4has an indentation 42 on each side thereof at the lower end, asindicated at 42, so as to form a recess to enable rubber band 40 to bindthe sack 38 or the other container thereto.

Operation With the device assembled as shown in FIG. 1, a motor, such asdrill 2, is connected to the outwardly extending reduced portion 17 ofshaft 16, as by a drill chuck 3, and the device is rotated in thedirection indicated by the arrow in FIG. 3. Styrofoam blocks, of suchsizes and dimensions as will pass through opening 25, are fed downwardso as to depress elastomer door 35, with the styrofoam blocks 26engaging the rotating cylindrical drum 18, whereupon the teeth 24 willgrind or grate the styrofoam into small particles, which will be carrieddownward between back 12 and cylinder 18, outward through the holes 34in semi-cylindrical, expanded metal member 30, with the disintegratedstyrofoam or the like being discharged out through opening 36 in thebottom of the housing formed by sides 4 and the front and back portionsand 12, respectively, which disintegrated material will be directed intoa sack or receptacle 38.

When sufficient material has been grated from scrap, hard styrofoamblocks, the motor 2 may be disconnected from the reduced portion ofshaft 17 by loosening the chuck 3, and the mill apparatus 1 may beunclamped from the table 8 by loosening C-clamp 6, so the device may beconveniently stored.

Having thus clearly shown and described the invention, what is claimedas new and is desired to be secured by Letters Patent is:

1. In a grinding mill for disintegrating hard, cellular, plastic blocksand the like, comprising;

(a) a housing including (1) side plates, (2) a front plate, and (3) aback plate,

(b) said housing having an opening formed in the upper and lower endsthereof, respectively,

(c) a cylindrical member journaled intermediate the ends of saidhousing,

(d) a spirally arranged toothed member attached to said cylindricalmember for rotation therewith,

(e) a shaft extending outward from an end of said cylindrical member forrotation of said cylindrical member therewith,

(1) said back plate having the inner surface thereof covered with anelastomer material, which material extends downward at least to ahorizontal plane passing through the axis of said shaft,

(2) a perforate, arcuate, semi-cylindrical member, having an end thereofextending upward beneath the lower end of said elastomer coveringmaterial on said inner face of said back portion of said housing,

(3) said back plate has spaced apart, outwardly extending elastomerbosses thereon, which bosses extend into close proximity to the teeth ofsaid toothed member, and

(f) power means adapted to be connected in driving relation with saidshaft.

2. A grinding mill for disintegration of hard, cellular plastic blocks,and the like, comprising;

(a) a housing including (1) side plates,

(2) a front plate, and

(3) a back plate,

(b) said housing having an opening formed in the lower ends thereof,respectively,

(c) a cylindrical member journaled intermediate the ends of saidhousing,

(d) a spirally arranged toothed member attached to said cylindricalmember for rotation therewith,

(e) a shaft extending outward from an end of said cylindrical member forrotation of said cylindrical member therewith,

(1) said back plate having the inner ,surface thereof covered with anelastomer material, which elastomer material, extends downwardly andinwardly across at least a portion of the opening formed in the upperend of said hous- (2) a perforate, arcuate, semi-cylindrical member,having an end thereof extending upward beneath the lower end of saidelastomer covering material on said inner face of said back portion ofsaid housing, and

(f) power drive means adapted to be connected in driving relation withsaid shaft.

References Cited UNITED STATES PATENTS 220,112 9/ 1879 Baker 146-182 X930,742 8/1909 DeMaio 246- 1,561,093 11/ 1925 McCargar 241-90 1,622,8493/1927 Ruprecht et al. 1,795,792 3/1931 Nielson 24l88 X 2,991,948 7/1961Humrnelen 24188 X ANDREW R. JUHASZ, Primary Examiner,

1. IN A GRINDING MILL FOR DISINTEGRATING HARD, CELLULAR, PLASTIC BLOCKSAND THE LIKE,COMPRISING; (A) A HOUSING INCLUDING (1) SIDE PLATES, (2) AFRONT PLATE, AND (3) A BACK PLATE, (B) SAID HOUSING HAVING AN OPENINGFORMED IN THE UPPER AND LOWER END THEREOF, RESPECTIVELY, (C) ACYLINDRICAL MEMBER JOURNALED INTERMEDIATE THE ENDS OF SAID HOUSING, (D)A SPIRALLY ARRANGED TOOTHED MEMBER ATTACHED TO SAID CYLINDRICAL MEMBERFOR ROTATION THEREWITH, (E) A SHAFT EXTENDING OUTWARD FROM AN END OFSAID CYLINDRICAL MEMBER FOR ROTATION OF SAID CYLINDRICAL MEMBERTHEREWITH, (1) SAID BACK PLATE HAVING THE INNER SURFACE THEREOF COVEREDWITH AN ELASTOMER MATERIAL, WHICH MATERIAL EXTENDS DOWNWARD AT LEAST TOA HORIZONTAL PLANE PASSING THROUGH THE AXIS OF SAID SHAFT, (2) APERFORATE, ARCUATE, SEMI-CYLINDRICAL MEMBER, HAVING AN END THEREOFEXTENDING UPWARD BENEATH THE LOWER END OF SAID ELASTOMER COVERINGMATERIAL ON SAID INNER FACE OF SAID BACK PORTION OF SAID HOUSING, (3)SAID BACK PLATE HAS SPACED APART, OUTWARDLY EXTENDING ELASTOMER BOSSESTHEREON, WHICH BOSSES EXTEND INTO CLOSE PROXIMITY TO THE TEETH OF SAIDTOOTHED MEMBER, AND POWER MEANS ADAPTED TO BE CONNECTED IN DRIVINGRELATION WITH SAID SHAFT.